Aston Villa boss Gerard Houllier has told Nigel Reo-Coker to curb his temper, after the former West Ham United star almost got himself into trouble during the 0-0 stalemate with Birmingham City.
Houllier substituted Reo-Coker after the midfielder was involved in a tussle with City's Craig Gardner, but he appeared to be keen to continue the argument when he came on to the pitch after the final whistle.
The Villa boss was unimpressed, saying:"Sometimes when you are tired you lose a bit of control and I didn't want to lose a player. I warned them and wasn't happy with the reaction. He will learn.
"We all know how competitive matches in the Premier League are but the Midlands derbies are maybe more so than others.
"You've got to be strong enough to take it on the chin and go on. In that particular circumstance the referee had whistled and it was a free-kick so we should get on with it."
Of the grim stalemate, the former Liverpool boss admitted:"We could have done better. Maybe it's because it's a derby and it's extremely tense, very tight and competitive.
"Both teams were extremely committed to the job and didn't allow many chances.
"It's a derby and sometimes they are not allowed to play. Credit to Birmingham they had a clean match. It was physical but not over the top and the referee dealt with the two teams very well."